Carbon/carbon (“C/C”) parts are employed in various industries. An exemplary use for C/C parts includes using them as friction disks such as aircraft brake disks, race car brake disks, clutch disks, and the like. C/C brake disks are especially useful in such applications because of the superior high temperature characteristics of C/C material. In particular, the C/C material used in C/C parts is a good conductor of heat and thus is able to dissipate heat away from the braking surfaces that is generated in response to braking. C/C material is also highly resistant to heat damage, and is thus capable of sustaining friction between brake surfaces during severe braking, without a significant reduction in the friction coefficient or mechanical failure.
C/C material is generally formed by utilizing continuous oxidized polyacrylonitrile (PAN) fibers, referred to as “OPF” fibers. Such OPF fibers are the precursors of carbonized PAN fibers and are used to fabricate a preformed shape using a needle punching process. OPF fibers are layered in a selected orientation into a preform of a selected geometry. Typically, two or more layers of fibers are layered onto a support and are then needled together simultaneously or in a series of needling steps. This process interconnects the horizontal fibers with a third direction (also called the z-direction). The fibers extending into the third direction are also called z-fibers. This needling process may involve driving a multitude of barbed needles into the fibrous layers to displace a portion of the horizontal fibers into the z-direction.
A circular needle loom may be utilized to form a circular preform, for example, for use in creating carbon brake disks. Various textile technologies exist for fabricating a continuous carbon feed form for a circular needle loom, including yarn placement, stitch bonding, pre-needling, and loom weaving with conical take-up rolls. Narrow fabric needle looms may be utilized to produce a continuous spiral textile tape to be utilized in a circular needle loom to form a circular preform. These spiral textiles may contain warp fibers which lie along the length of the textile, and weft fibers which lie along the width of the textile.
Significantly, prior art looms and other apparatuses for manufacturing circular preforms suffer from inefficiencies in the manufacturing process. For example, a brush bed plate for a circular needle loom may be utilized to prepare a net shape brake preform. A rotary brush bed plate may be utilized to meet the transport and needling specifications of a thicker fibrous structure like a brake disk preform. However, maintenance and cleaning of the brush bed plate, and removal of the finished preform from the bed plate create extra steps in the needling process. These extra steps, among other reasons, substantially add to the time required to manufacture the preform, resulting in reduced efficiency, lower output and increased cost. Such brush bed plates are therefore generally not suitable for high production rates, and it is desirable to develop a system and method for increasing the efficiency of the manufacturing process to result in higher production rates and reduced costs
Furthermore the brush bed plate does not always provide sufficient anchorage of the bottom layers, resulting in some cases of preform transport interruption during fabrication. The characteristics of the brush may change over time, thus resulting in higher maintenance and possibly in higher part to part characteristic variations than a smooth bed plate.
Additionally, existing systems and methods for manufacturing circular preforms may produce preforms that have undesirable properties. For example, a soft brush bed plate is compliant, and this compliancy may result in preforms with lower than desirable fiber volume. The lower than desirable fiber volume may result in a preform that is of lower quality.
Another reason for the deficiencies in the prior art with respect to quality of the preforms and the manufacturing efficiency is due to the complexities involved in working with a spiral textile. For example, the curvature of the spiral textile may require circuitous routes from a textile reel or feed system to the circular needle loom. Additionally, the texture and structure of the textile makes it difficult to deposit layers of the spiral textile on the circular needle loom. Furthermore, existing layering and needling processes make it difficult to remove the needled preform from the needle loom.
Significantly, prior art mechanisms and methods for transporting a spiral textile from a loom (where the textile is woven) to a circular needle loom require much more space in order to deliver the spiral textile in a complex path to the circular needle loom. This complex path is utilized in order to maintain the weave and overall shape of a spiral textile from the time it leaves the fabric needle loom to the time it is deposited in the circular needle loom. For example, the spiral textile may by layered horizontally on a spool as illustrated in FIG. 1, such that it is removed from the spool and oriented to be disposed horizontally on a circular needle loom. As can be appreciated, such a configuration requires that the textile tape change directions from the spool to the circular needle loom, resulting in a circuitous path from the spool to the loom.
It is thus desirable to develop a system and method for preparing net shape preforms from a continuous textile spiral feed that are not only suitable for high production rates with a high degree of repeatability, but that are also capable of producing preforms of a higher quality, for example, with a higher fiber volume. It is also desirable to develop systems and methods that utilize various mechanisms in conjunction with positional structure and/or to create positional structure of the spiral textile to facilitate layering and needling the spiral textile in an efficient manner to produce high quality needled preforms. Furthermore, it is desirable to create needled preforms in a manner that facilitates simplified removal of the preform from the needle loom. Moreover, it is desirable to develop a circular needle loom that reduces waste generated during the process of creating the brake disks.
Additionally, it is desirable to develop a mechanism for more conveniently transporting the spiral textile tape. It is further desirable to reduce the amount of space required to transport the spiral textile. Moreover, it is desirable to transport the spiral textile tape while reducing distortions in the weave of the spiral textile that are generated in existing spiral textile transport mechanisms